[Dsg-rich] Mirror 3 reflectivity results for bad areas

[Marco Mirazita]

Hi all,
I just realized that other measurements on Mirror 4 have been done, I 
added also these to my plots.
To summarize the results:
- The measurements on spot 3,4,5 on mirror 4 taken on August 18 are 
suspicious.
- We have a reflectivity of about 90% in good areas of the mirrors
- In spots with visually bad surface, we have typically a decrease of 
the reflectivity without changing the wavelength dependence. The 
decrease may range from few percent to up 15% as for spot 11 of mirror 4
- There are two examples of very bad reflectivity on spots 8 and 10 of 
mirror 3, where not only the reflectivity is low, but also the 
wavelength dependence is severely modified

Marco



Il 2017-08-24 14:55 Marco Mirazita ha scritto:
> Hi all,
> I made plots of the latest data from Tyler and companies on mirror 3,
> see attached pdf reporting also the plts from previous measurements.
> The photodiode A is acceptably stable above 400 nm, even if not as
> stable as during the measurements taken in July.
> The reflectivity is definitely bad on two spots:
> - the hole in the middle (spot 8)
> - the "imprint from the foam" spot on the lower left corner (spot 10).
> In all the other spots the reflectivity shape is the same of the
> previous measurements in July on good spots, but it is about 5% lower.
> 
> If it is possible, I would like to repeat the measurements in spots 8
> and 10 and add a measurement on the lower right
> corner.
> 
> Marco
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